SPC AC 301555
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0955 AM CST TUE DEC 30 2003
   
   VALID 311200Z - 011200Z
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 75 WSW TUS 50 WNW SAD
   LVS TCC PVW CDS SPS SEP 55 SSE BWD 30 SE JCT DRT.
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...SYNOPSIS...
   PROGRESSIVE AND DEAMPLIFYING UPPER AIR PATTERN IS FCST ACROSS CONUS.
    TROUGH NOW OVER ERN STATES WILL MOVE ACROSS NWRN ATLANTIC AND
   CANADIAN MARITIMES...LEAVING BEHIND RELATIVELY STABLE CONTINENTAL
   BOUNDARY LAYER OVER MOST OF CONUS E OF ROCKIES.  CONTINENTAL AIR
   MASS TRAJECTORIES WITH PARTIAL MARINE MODIFICATION WILL RETURN NWD
   ABOVE BOUNDARY LAYER OVER NERN MEX AND SRN TX...BENEATH SWLY FLOW
   AND AHEAD OF TROUGH NOW IN FORM OF CLOSED CYCLONE OFFSHORE SRN
   CA/NRN BAJA.  THIS LOW SHOULD BECOME OPEN WAVE AGAIN EARLY DAY-2
   OVER BAJA BEFORE EJECTING NEWD ACROSS NM...AS RAPIDLY WEAKENING AND
   POSITIVELY TILTED PERTURBATION.
   
   ...SWRN CONUS...
   ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE AFTERNOON INTO
   EVENING OVER WRN PORTIONS OUTLOOK AREA...SERN AZ AND S-CENTRAL/SWRN
   NM.  LARGE SCALE DESTABILIZATION -- PRIMARILY IN FORM OF MIDLEVEL
   DPVA -- WILL COMBINE WITH SFC HEATING AND MARGINAL MOISTURE OVER
   SONORAN DESERT AND ADJACENT MEX MOUNTAIN RANGES TO GENERATE MLCAPE
   GENERALLY AOB 300 J/KG.  THIS SHOULD RESULT IN HIGH-BASED DIURNAL
   CONVECTION...SOME OF WHICH MAY CROSS SERN AZ/SWRN NM BEFORE SFC
   INSTABILITY IS REMOVED BY EVENING RADIATIONAL COOLING. NEWD SHIFT
   OF LARGE SCALE ASCENT WILL YIELD STEEPENING LAPSE RATES AND SOME
   RISK FOR THUNDER THROUGH EVENING ACROSS SRN/ERN NM.  TSTM
   PROBABILITIES WILL DECREASE WITH NEWD EXTENT AS PRONOUNCED DAMPENING
   OF MID/UPPER TROUGH OCCURS AND ASCENT WEAKENS.
   
   POTENTIAL FOR EPISODIC/ELEVATED TSTM DEVELOPMENT WILL INCREASE WITH
   TIME OVERNIGHT ACROSS PORTIONS W-CENTRAL TX.  SWLY MIDLEVEL FLOW AND
   LOW LEVEL WAA WILL BE IN PLACE OVER SRN HIGH PLAINS PRIOR TO TROUGH
   PASSAGE...CONTRIBUTING TO DESTABILIZATION.  ACCORDINGLY...ETA/NGM
   EACH PREDICT SUBSTANTIAL MOISTENING AND STEEPENING OF LAPSE RATES
   THROUGH 700-500 MB LAYER AFTER 3Z...WITH 25-35 K INDICES AND UP TO
   200 J/KG MUCAPE DEVELOPING.  THERE MAY BE RELATIVE MIN IN TSTM
   POTENTIAL OVER PORTIONS W TX AND/OR SE NM...IN BETWEEN REGIMES OF
   WEAKENING DYNAMIC ASCENT ACROSS NM AND TX PANHANDLE AND INCREASING
   LOW LEVEL MOISTURE OVER CENTRAL TX AND RIO GRANDE VALLEY. 
   HOWEVER...CONFIDENCE IN MESOSCALE POSITIONING OF
   MOISTURE/INSTABILITY MINIMA ALOFT IS TOO LOW ATTM TO CALVE OFF ERN
   LOBE OF THUNDER OUTLOOK AS SEPARATE ENTITY.
   
   ..EDWARDS.. 12/30/2003
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED FOR 0800Z